We have people connecting to a WAP that we are in charge of, but dont have admin access to, the service provider tells us that individuals are using the WiFi to download stuff, assuredly movies and other such stuff. Is there a tool that could dissociate wireless clients?

If it's someone whose supposed to be using the AP that is responsible for the questionable behaviour as identified by the ISP, then no wireless security measure is going to help anyhow.

An acceptable use policy may be some cover from any comeback on yourselves from it's abuse (I'm not a lawyer, so don't take that advice as absolute).

If it's someone that's not supposed to be using it, the problem with any disassociation method is that it will be MAC based as far as I'm aware. Whats to stop them from changing their MAC address and regaining access?

Anyhow, in addition to the advice already given, Aireplay from the Aircrack suite can also achieve this.

How are you required to be in charge of it, if you don't have admin access to it. What do they expect you to do, to be in charge of it?

Is the ISP in charge of it?

Maybe overkill, but figure out where those people are connecting from, if possible. Deploy fake WAPs in those locations. Access points without internet access. Same name, stronger signal than the real WAP. Look into authentication options if you can.

Disassociating clients is just a temporary measure that the client can easily work around. Better to just secure the AP itself to prevent these people from connecting. If the ISP expects you to secure it, tell them to give you admin access, or have them send someone with admin access to deal with it.

Wireless issues aside, you could deploy Untangle behind the AP and filter any torrent-like activity, and block other undesirable stuff. You could also present an Acceptable Use policy users must click on.

I ran into a similar situation at a public library that offers free open wifi. The Untangle box made all the would-be torrent folks pick up and move on.

This is a basic rundown, we are using temporary site, and there is a contract here that provides for wireless access. When we originally came to the site, the wifi was decent. We noticed significant issues as time went on, from users only being able to load 1-2 pages, ect. Well, the bosses called the company who did a survey. They stated it was users downloading from the living area while they were at the work site. Now I suggested that they ask the company to block the commonly used torrent ports and such, ultimately I am not in contact with the company myself, but my understanding is that the contract puts them in charge of the wired and wireless AP's, but we as the customer have some sort of support.